Gas turbine engine stator vane asymmetry

Abstract

A gas turbine engine includes an array of airfoils that include first and second segments. The first segment includes a first number of airfoils that are circumferentially spaced from one another a first angular spacing. The second segment includes a second number of airfoils that are circumferentially spaced from one another a second angular spacing. A sum of the first and second number of airfoils corresponds to a total number of airfoils in the array. The first angular spacing is based upon a first effective number of total airfoils in the array that is different than the total number of airfoils.

What is claimed is: 
     
       1. A gas turbine engine comprising:
 an array of airfoils including first and second segments, the first segment including a first number of airfoils circumferentially spaced from one another by a first angular spacing, the second segment including a second number of airfoils circumferentially spaced from one another by a second angular spacing, a sum of the first and second number of airfoils corresponding to a total number of airfoils in the array, the first angular spacing based upon a first effective number of total airfoils in the array that is different than the total number of airfoils, wherein the first effective number of total airfoils in the array is an integer plus 0.5, wherein each of the first and second number of airfoils is at least three. 
 
     
     
       2. The gas turbine engine according to  claim 1 , wherein the array consists of two arcuate segments that are each approximately 180°. 
     
     
       3. The gas turbine engine according to  claim 1 , wherein the first angular spacing is 360° divided by the first effective number of total airfoils in the array. 
     
     
       4. The gas turbine engine according to  claim 1 , wherein the first and second numbers of airfoils are different than one another. 
     
     
       5. The gas turbine engine according to  claim 1 , comprising a turbine section, wherein the array is arranged in the turbine section. 
     
     
       6. The gas turbine engine according to  claim 5 , wherein the turbine section includes a fixed stator section and a rotating section, the first and second number of airfoils arranged in the fixed stator section. 
     
     
       7. The gas turbine engine according to  claim 6 , wherein the array of airfoils is configured to produce a forcing function for the rotating section that is approximately 180° out of phase with a subsequent revolution of the rotating section. 
     
     
       8. The gas turbine engine according to  claim 1 , wherein the first effective number of total airfoils and a second effective number of total airfoils in the array are fractional numbers. 
     
     
       9. The gas turbine engine according to  claim 8 , wherein the first and second angular spacings each respectively correspond to 360° divided by the first effective number of total airfoils in the array and 360° divided by the second effective number of total airfoils in the array. 
     
     
       10. The gas turbine engine according to  claim 1 , wherein a second effective number of total airfoils in the array is another integer plus 0.5. 
     
     
       11. A gas turbine engine comprising:
 an array of airfoils including first and second segments, the first segment including a first number of airfoils circumferentially spaced from one another a first angular spacing, the second segment including a second number of airfoils circumferentially spaced from one another a second angular spacing, a sum of the first and second number of airfoils corresponding to a total number of airfoils in the array, the first angular spacing based upon a first effective number of total airfoils in the array that is different than the total number of airfoils, wherein the second angular spacing is based upon a second effective number of total airfoils in the array that is different than the total number of airfoils, wherein the second effective number of total airfoils in the array is an integer plus 0.5, wherein each of the first and second number of airfoils is at least three. 
 
     
     
       12. The gas turbine engine according to  claim 11 , wherein the second angular spacing is 360° divided by the second effective number of total airfoils in the array. 
     
     
       13. A gas turbine engine comprising:
 an array of airfoils including first and second segments, the first segment including a first number of airfoils circumferentially spaced from one another a first angular spacing, the second segment including a second number of airfoils circumferentially spaced from one another a second angular spacing, a sum of the first and second number of airfoils corresponding to a total number of airfoils in the array, the first angular spacing based upon a first effective number of total airfoils in the array that is different than the total number of airfoils, wherein the second angular spacing is based upon a second effective number of total airfoils in the array that is different than the total number of airfoils, wherein the first effective number of airfoils in the array corresponds to the second effective number of airfoils in the array plus an integer, wherein each of the first and second number of airfoils is at least three; and 
 wherein the first segment and second segment are each a single contiguous arcuate segment that is approximately 180°. 
 
     
     
       14. The gas turbine engine according to  claim 13 , wherein the first effective number of total airfoils in the array is different than the second effective number of airfoils in the array.